Methods are known for example from the "Encyclopedia of Medical Radiology" Vol. 1, part 2 (1965), pages 203 to 212, wherein tomograms are produced with X-rays or similarly penetrating radiation by scanning of the subject under examination with a beam of rays emanating from a source and wherein the beam which issues from the subject under examination acts upon a recording device, the source and recording device being moved in unison to bring about the scanning of the desired bodily layer.
In the known apparatus for producing fluoroscopic tomograms with X-rays or similarly penetrating radiation, at least one element from the group: radiation source, examination subject, and recording device, is moved. Depending upon the methods and recording elements employed, the patient is, as a rule, kept motionless in medical diagnosis. The radiation source is displaced. This requires a great outlay of energy and time also. On the other hand, generally a braking is again necessary at the end of the photographic exposure which likewise demands considerable outlay.
Regarding the method, however, the decisive factor is the process of setting into motion itself, because this enters into the time requirement of the actual photographic exposure. In the case of conventional apparatus for photographing linear layers, 600 milliseconds (600 msec) have been shown to be the shortest photographic times. More rapid photographic sequences (or operating cycles) are possible only with a large outlay. However, in so doing, only a reduction by half of the shortest tomographic photographic times which are otherwise possible can be achieved as a rule. In order to photograph moving organs, such as the heart, tomographic times of 80 msec would have to be obtained. Taking into consideration the movement sequences of individual parts of the heart within the heart-phase, moreover, a tomographic time of 20 msec appears desirable. Rapid movements such as this cannot be obtained with the mechanical means presently available.